java - 如何使用java代码检查邮件是否未发送

Question

我使用以下代码发送邮件

public class Mail
{
    public static void main(String[] args)
    {
                String[] to={"abcd@xyz.co"};
                String[] cc={"pqrs@xyz.com"};
                String subject = "Subject";
                String body = "This is Body....!!";

        Mail.sendMail("From@gmail.com","Password","smtp.gmail.com","465","true",
       "true",true,"javax.net.ssl.SSLSocketFactory","false",to,cc,
       subject,body);             
    }



  public synchronized static boolean sendMail(String userName,String passWord,String host,String port,String starttls,String auth,boolean debug,String socketFactoryClass,String fallback,String[] to,String[] cc,String subject,String text)
{
            Properties props = new Properties();
            //Properties props=System.getProperties();
    props.put("mail.smtp.user", userName);
    props.put("mail.smtp.host", host);
            if(!"".equals(port))
    props.put("mail.smtp.port", port);
            if(!"".equals(starttls))
    props.put("mail.smtp.starttls.enable",starttls);
    props.put("mail.smtp.auth", auth);
            if(debug){
            props.put("mail.smtp.debug", "true");
            }else{
            props.put("mail.smtp.debug", "false");         
            }
            if(!"".equals(port))
    props.put("mail.smtp.socketFactory.port", port);
            if(!"".equals(socketFactoryClass))
    props.put("mail.smtp.socketFactory.class",socketFactoryClass);
            if(!"".equals(fallback))
    props.put("mail.smtp.socketFactory.fallback", fallback);

    try
    {
                    Session session = Session.getDefaultInstance(props, null);
        session.setDebug(debug);
        MimeMessage msg = new MimeMessage(session);
        msg.setText(text);
        msg.setSubject(subject);
        msg.setFrom(new InternetAddress("From@gmail.com"));
                    for(int i=0;i<to.length;i++){
        msg.addRecipient(Message.RecipientType.TO, new InternetAddress(to[i]));
                    }
                    for(int i=0;i<cc.length;i++){
        msg.addRecipient(Message.RecipientType.CC, new InternetAddress(cc[i]));
                    }
        msg.saveChanges();
                    Transport transport = session.getTransport("smtp");
                    transport.connect(host, userName, passWord);
                    transport.sendMessage(msg, msg.getAllRecipients());
                    transport.close();
                    return true;
    }
    catch (Exception mex)
    {
        mex.printStackTrace();
                    return false;
    }
    }

代码工作正常并且消息已发送。但如果消息尚未发送(例如当我尝试发送到 abcd@xyz.com 因为它的邮件 ID 无效时)，我想设置一个标志(例如 flag=false)。如果有人能在这方面帮助我，我将非常感激。

提前致谢

Answer 1

您可能需要将实际的电子邮件放入 msg.setFrom() 中，并检查其收件箱中是否有 Non delivery report .

大多数服务器会在放弃之前多次尝试发送您的电子邮件，因此您无法立即确定该电子邮件是否有效。